Supervisory circuits



H. F. SHOFFSTALL sUPEnvIsoRY CIRCUITS Nov. 1 0

Filed Nov. 12, 1921 2 Sheets-Sheet l Lseomo Nov. 10I 1925 H. F. SHOFFSTALL SUPERVISORY CIRCUITS Fild Nov. 12, 1921 2 Sheets-Shen 2 Patented Nov. 10, 1925.

PATENT lorries.

HUGH r. snorrs'rALL, or NEW Yoan, N. Y.,`Ass1eNon-roniana1cnN TELnrHoNE Nn 'rameaux COMPANY, .e conronA'rIoN or Naw vom;

sUPEnvrsonY CIRCUITS.

Application led November 12, 1921. Serial No. 514,695. "i i To all whom t may concern Be it known that I, HUGH F. SHorrsTALL,

residing at' New York, 4in the county of Bronx and State of New York, have `1nvented certain Improvements in Supervisory Circuits, of which the following is a speciication.

This invention relates to an improvedv type of supervisory circuit and apparatus adapted to be utilized with telephone lines.

In a co-pending application filed June 18, 1921, in` the name' of Ray S.'v Wilbur, Serial No. 478,494, there is illustrated a telephone circuit including a two-element, two-way v repeater, together with arrangements whereby supervisory apparatus may be associated therewith. In this applicatlon the super- Visory circuit is associated with the telephone line through an additional winding'on the output transformers ofthe repeaters. It isa special feature of this invention to provide supervisory apparatus and circuit arrangements which' are particularly adap'tf ed to be associated with the circuits of the aforementioned application, although they may also be utilized with other types of tele#` phone lines. v

With the supervisory arrangements of this invention the repeater attendant may monitor both ways on the repeater set without operating any keys. monitor either on the east orY west* output coil alone'by variantly operating the monitoring key provided in|the arrangements.

The invention furthermore' provides im.

proved arrangements for talking from the supervisory circuit on the repeater circuit, in that -a talking key is provided whereby the telephone set of the repeater attendant may or may not be connected to the super' visory .windings through` an inequality ratio i With this arrangement it' is .possible to -.talk overl the circuit eitherl repeating coil.

.through the inequality coil or not, as de-v sired.

It 1s also possible to -A further, feature of the invention cony ring on the circuit through the supervisory windings of the output coils. In suchcircumstances' with the arrangements' of lthis invention, means are provided whereby the ringingapparatus itself may be controlled by the repeater attendant from the supervisory apparatus. Arrangements are also provided when ringing takes'place directly` through the supervisory windings ofthe output coil for'preventi'ng'the ringing current 65 from magnetizing or injuring said coil or its windings. Other featuresand purposes of the invention willappear more fullyv from .the detailed description hereinafter given.

The invention ma be more fully under. stood from the fol owing description, to-

getller with the accompanying drawing, iny Figures 1 and 2 of which is illustrated a' circuit diagram embodying rangement of the invention.

In`Fig.'1 there is illustratedtwo line sec` tions L1 and L2, whichare interconnected a'preferred arthrough a two-element, .two-way fre' eater comprising the vacuum bulb .ampli ers' 1v and 2 which 'are well-known in the., airtu'e 'iIhe S0 output circuits of the amplifiers'fil.l nd2l are coupled to-the'lines L1' "Rand .Lzathrougth the usual type of three-winding transforin- &1.v ers, such as the transformers 3 and s4.. As-'1L' sociated .withthese transfor'n'iers arer the j S5v balancing networks N1 and N2. i' "For the purpose of supervi'slng on the lines L, and

2, an additionalwinding `isjprlovided-on each of the outut transformers Sand` 4,

such as the windings 5^a'nd 6. These wind- 00 ings are' connected over the circuit-7y to the supervisory jacks'Jl, whereby-:the 'super-v visory circuit of Fig. 2 ma Vbe fconnected-- to the lines, aswlll be pointe outlater. -As

the repeater apparatus is generally provided v,05

connected j a's a separate unit, it' is-.usua1l to the linelsections Il, and Lr2 t rough line 1 jacks such as jack Js and jackfJ. F-urthermore, in some instances ringing/apparatus t may be assoclated wlth the line 1n order 100l to relay ringing current around the repeater apparatus. Such' apparatus is lwell-known in the art and no further description thereof will be' given. When such apparatus .is

such as 8 and 9- may beiassociated with the f line between the ringing apparatus and the repeater apparatus topprevent the ringing currents from` entering the repeatera tus. These filters, vhowever, will rea .associated with the lines, high pass filters 405.

" J1," as will be pointed-,outlaten the, key

15W. inattesa f uit feasts uit tat f1 re-y.. to' 45; n una frequency telephonicwurrents and, may.

to G. A. Qampbell, 1,22 7,113. The rela-ys thrown to the left, theoperatonstalkingiset 1 2, 13, 12 and:131are` rin iin rela s which 25'willfbeconnected through the ine ualityil g y q .in-timmy wellcoil 22:.to bothpof the lines L1 .and L2, s'o that apparatus. 'the operator may talk over both .of said lines t e .relays at the saine. time. When key K ,is thrown would normally l bef0un 1 n knowntypes. of composite ringer The vleads. v10 and @11 interconnect y e in theusual'mannertogthe upper'ltipr-con'tact of thetypeyillustrate'din Ithe U.; S'. patent lofjack J1. KAccordingly,whenfthekeyK,fis; l

of the, parts. of` the ringingl apparatus of tothe lefty acircuit is closed .fromground each. line inI the customary manner-...VA through. the winding'of'-relay-37,130 battery, patching cord 14 isshownor connecting operating relayl 37. and changing receiver thelSllPeIViSOly apparatus either totheline leads from normaljpositiontoindution: coil jacks J 3- and Jlgor to` the supervisory jacks Afor talking position. Ifwhen fthe key K, is

In Fig "2 isillustrated the-.supervisor5ir nected through the coil' 'as described, it

thrown to the left; and the talking lsetfis. concircuit and .arrangements ofthe invention. yshould be desired to talkfon either ofythe In this circuitv there is .provided the ol'nertk.` linesv L1 and L2 alone,the key K1 `will be torfs telephoneset, consisting of the transthrown eithertothe. right orfto. the left. .If

mitter 25 andthe receiver 24;..1 There .is also thekey K11 iysthrownltov .the right in order yto provided atalking key K1,l and .a monitorin ta'lkover the line L1, only. one fofstheleftkey Thefsupervisory circuit is l.provide hand windings of the coil 22will.be uvtili'zed.`

with ythe jacks J5'. Whenihe :supervisory The circuit arrangement therefor will be as circuit` is connected through they patching follows: from.; terminal/1 6, conductor .i 17,1 cord 14 .to` vthe Islllpervisory.jacks J1- andthe right-hand make contact of key K1, conducf monitoringtkey is din its normal position rtorv39,y.1efthand breakvcontact `of key K1, as shown, thev operatorls' telephone receiver com luctor-O, Iet-handmakecOntact.of key 24W`11y be S0 Connected t0 the Supervisory K1 kto conductor .41, and thence in sthe usual windings 5 and ythatthe repeater attendant manner lto theI upper sleevefcontact'ofjacks maymonitor both ways@ on :the repeater se# J1, and from the terminal l44, over conductor without 1 l 1 to ythe left,;lthei attendant may ductorf, and thence` in the usual manner to connect thereceiver 2li directly to.tl 1 esuperV the .upper tip contact'. of .jacks-. J5. Accord? visory windingjG and hencemay monitor on ingly, when the key Kafis thrown to the left Y. the line L2 alone. l By throwing the keyv .and the key K-"1 is thrown tothe right, Mtht', l11o .the righwthe telep hone .reee1ver-24Imayw-be operatersftalklngtsete.wi11.beconnected directly connectedfto-the supervisory .Windonly :to the. line; vand transmission.: will ing 5' and the attendent my'mOIltOlQIlth' 'take placefonly throughthe upper vleft-hand line Lf1alone.-v `Resistztnces 65 and 66 mag provided inseries with the .receiver to re u ee providing for maximum .talking eiciency on the, current. to lthefdesi red fvaluewhen 11.10111: a Aconn'ectlon with only onegofjtheflines. If,

tol'ing"r .ASSOatP/d Withfthftflking keyf under suChiCndtiQDS, ifslhould, b .desired iSl 111.1 inequality rati() Tepetmg-COIQ IThis totalkon the line 'L.a1one, the key 1would "inequality ratio I soil@ is I'provl'ced t0 Secure be. thrown tol the' left... .Under theseGii'unfl-v maximum stalking efficiency onthelines, .in st.alvl.ces,`fthe `upperleftl-iand- Winding. of the somennstances thel talkingicurrenhbeing inequalityjcoill22 wouldbe conneetedtothe fIflIlSlllttd` 'tlllOUgh all. 9 f .the Cgil-11nd, .1 1! contacts of Ij ackgin the followingamanner other instances vthev .talk-1ng` cu 1.r "snt`v being. 'from.terminal.46, conductorsi( and 48,1 left-f transmitted merely through a'portiongofrthe handmakecontactof'key1K1, conductor 40,' coil.' yWhen the key K11 1s` lthrown' to the left,v lefthand .make contact .of kev.y K, ,1to1 con: 1

the ,talking1,setf-25 .wilLbe' connected to the ductor 41, and -thencein the. usual manner vvto' lines -throughathe Ymequahtycoll 22 `mthe theiipper sleeve.. contactofljack J1, and

following llmll' 1. Th-tlkingsgetwill nor-1 from terminal/A4,; over conductor .42',gleft mally be connected over conductors 30,;.e0nhandjnxakecontact of keyKa-to :conductor tactsandi armaturesofrela1.,*231and lcondlle- 45, and,thencfe. .fin thdusu'al m'annergto the 1 tors 31tothe-rightfhandwinding of .coil .22. y lowertip vecrit-acti of,juclrJ `.When the key Thetrcultsfor .f4101111@@nur.4211@5 left-hand is* thrown. to. th'erisht tile windin of 1011.22.10 thezaeksialisas rfob. will he wnnected. dimly to the lines. Withlowsr rm terminal 0V 22, 'over condiictor42, left-hand 1 manner.

the-,usualmente tthetlowertii ontctot eeducwrsofsthe sul 'rvzsr' iajckJeandtimmfthefterminelt44 QLthwQl :thetoontcts @ef keys tana n' throwin die.

perating any keys. By' throwing 42, left-hand inakecontactofkey K, toconbe half'zof' the .inequality ratio 011.22; .thereby transmitter. 25

Ethe.con.122,s0n-1 out the inc-mien .qi-the come, .in .inc ...fol-

' eitherto the left or totheright aftcrthe.

v talking key K3 has been operated, the transmitter 25 may be selectively associated with either of the coils 5- and 6, and hence may be connected toveither of the lines L1 and L'z alone. It is pointed out that when the key K3 is thrown to the right, the following circuit will Vbe closed: from ground, lower-right-hand make -contact of key'K3, conductor 35winding of relay 23,"conductor 36, winding of relay 37 to battery and ground. This circuit will energize the relays 23 and 37, which will disconnect the conductors 30, leading .to the of the lcoil'22and will change the connection of the'receiver from its normal position to the induction coil; for'talking.

Associated with "the ringingvkey K2 is a source 18 of 135 cycle ringing current, a source 19 of 20 cycle'ringin current, and the relays 15, 16 and 17.l T e relay 15 1s connected over conductors 54 and 55 to the lower sleeve contact of jack J5 and has' a winding of relatively high resistance for purposes which will be pointed out laterL The source 18 of 135 cycle current '1s nor'- mally connected throughthe resistanceelements 2G and21, and conductors 49 and 50 to the left-hand contacts of key K2. The resistance elements 20vand 21 are provided, so that when 'ringing takes place' directly. through the supervisory windings 5 and y6, the full force .of the ringing generator 18 -will not be applied y,through said coils, so

that said coils are not apt to bemagnetized .or injured. These resistance elements may be short-circuited upon the operation of rclay 16. when ringing takes place directly over the line, as will be pointed out later. The source 19 of 20 cycle ringing current is associated with the right-hand contacts' otv key K2 over conductors 52 and 53,. but is normally Vdisconnected therefrom, the connection being controlled by the cont-acts of the .relay 17. vThen the jack J5 is connected to the jack J, and it is desired to ring directly through the supervisory windings,- such as 5 vand 6, the key K2 will be operated.

It is pointed out that in general vit is the" practice to ring through such windings only with current in the nature of 135 cycles, and accordingly. the key K2 would be thrown to the left. When the key lK2 is thrown to the left, a circuit will be closed'from ground,

and the upper make contact of key K2, over conductor 51 to the generator 18, thereby starting the generator into operation- Ringing current will then be. applied from the 'generator through .the resistancev elements 20 and 21, and over conductors 49 and 50 to the left-handv makecontacts 'of key K2, and

thence over lthe contacts'of key K1 to the contacts off jack J5. It isA pointed out thatl byoperating the key lK in lconjunction with the key K5 this current may be sent set 25 from the right-hand winding,v

directly through the supervlsory windings on the output coils. In such cases, the jack J5 will not be patched to theA jack J1, but will be patched directly to one of the line jacks, such as jack Js or jack J4. The reason that it may not be possible to ring directly through the ,supervisory windings. when intermedlate rlngln'g apparatus is .asf

sociated with t-he lines is because when such apparatus is provided, there may be provid-v ed Ain the line, bet-Ween such apparatus and the line jacks, apparatus such as 8 and 9, which may be a lter adapted to readily vallow the transmission of telephonie currents, but which prevents the transmission of currents ofringing .vfrequency In ac-l cordance with ythis invention, thesleeve contacts of the line jacks are .connected by the conductors 56 and 57 to theoperating Vcircuits of the rin'iner relays ofv he ringlng :lpparatus, suchabs'tlie relays land 13. Ac-

cordingly,`should.rit be desired yto ring'ove-i` al1n e such as "the line L1 when intermediate rlnging apparatus is provided between the line L1 and the line L2, the jack lJ5 will be connected by the patcninef cord 14 to the iack J 3 and the key K2 would be o rated. When the key .K2 is thrown to the eft the following circuitlv`- will be.. closed: vfrom ground, Vlower `lefthand "make contacts of key Kmconduc'tor 61, conductor'55, lower sleeve contact ofv jack J 5, sleeve contact oi jack J3, conductor 56, winding of relay 12 to battery andground. v ,The closing of this circult serves `to operate the relay 12. Thel operation of the relay '12 will apply 135 vcyclering1ng current to'pthe .line'Lr The key K2 mightv also'be thrownv to ther-ight.

This would'a'pply current yfrom conductors y 63 and 55to the relay 12, and operaterelay 12 in substantially the same manner as` has already been described. The relay 12, under certain conditions` might lbe adapted to send e out. over the line L1 20 cycle ringing current The j instead of! l cycle ringingcurrent. p ringing operation, 'should the jack ,Jrfbe connected to, the jack J4 in order to ring over 4thelne L2, would be substantially the same as has been described with respect to the Will be given. 4

- Should he lines L1 and L2. not beproline L,l and no further `description thereoi vided with intermediate ringing apparatusv the high 'pass filters Band 9 would be-omltted andthe conductors 56 and 57 would be di-.

rectly connected to a source of current such as abattery similar tov that shown associated with relay 12. Under conditions the 'it desired to rigont over lineLl the jack J, would oc oonnccccdoy Acon pinching cord 14 fo ino jnckiJg. ,This would clone Acho foilowingl circit: from ground and bttiy, 'conductor 56, sleeve contctsjof jack J5,

/i-,iirongh ohcipatohing cord 14, lower sleeve "c'ontnco` of jock J5,` conductors 55 andv `54, 'windingof relay 15, to ground. The rclny v15 is 'provided 'with n high resistance winding"so that when th J is conilcotcd with li'e ihldntr Hilfti-'Ilflldi"it'e ihg'lg" i nclays, "schfas `12, "as hoctofoij described,

th relay '12 will not operate. The relay 15, npon operacion,- will closc Aclic following cir-` coin: from ground, nrinaturc ond contact of relay 15,'condnctor 5s, winding of -ifcloyV 16, condiictor 59, Winding of rly `17 to bottery 'finti`r 11nd; T his' will opernitctherelziy 16 ond t cfrclny 17. *,'Ifnc operacion of relay 1o short-circuits about. `the ro-v Will clSo s i'stance lemcnt 20 rind V 2 1 So that thcfull force 'of-the ringing genontor 18 m be applied conductors@ sind' 50 'and t icnc'e to the line. The operation of relay 17 will di- Aro'cily conn'cct thc Source l19 to thc conductors 52 s111653. If it' is desired-to ring ont over the lino with' y135 cyclo -curi-cnt the' key 2 'will thrown to they loft `aridi-he following circuit will .be' closed. From ground Vrid `'circuit 51 tothe opportuno 18, niic'rcby 'starting it in operation to apply ,135 cycle current to conductors 49 and 51. The followcircuit willolso be closed: from ground,

'lcihand maize contact of kcy K2, conductors 60 kand.*62,@conflict and 'ninatuc of relay 16, winding of relay 16, conductor 59, winding otnrclay T17 to bnctcrynnd ground, thereby holding thercliys- 16 and 17 in energized condition independently' of .thc opertion 'of' oly 15'. ,.Thj 135 oyclc'ringing curr-cnt will thon be opplicd in full force to conductors- 49 fnd 50 and th'cnccI over thocontacts of. kyfs K2* and Ki, in `a mller alr'ady'd lscnibjotl, to thecontacts of ook J and thence tothe lille L1. Sholiid it' f desired to iifgv out ofvline ,L1 with 20 cyclo 'current fthe vvillinid apily 20 cyclo current, from source 1,19 .tocov' 4fictors 52* ond 53j and ythcnc over contacts' f'fkey's K, and Ki and iclis Jo and ringing( opcrocion, 'should-coc jock .Loc con.

sonic ns1-nis -bcenfdesobed with respect' to ,certain .specific nrrcngcmcntnnhich nrc desirable, it is 'understood that ic is cannon-of 'y f fno iii-other und widely varied forms withot dopartin ,from the' -spir'i'tf of the invention ns define in thc 'apfypndod claims. What is "claimed is': y y

y1. Tho-combination ywith ayrepeoter circuit ooinprising lpcrvisory wind-ings on 'the outpit trahsflis f of' the ropeiter, and -mhitbring 'jacks ssoiatedtwithsoid windings; of a jsinpcrvisory circnitr comprising -switching moans; or oonnocting said supertwo=wa`y repeater Acircuit comprising `suporvisor'y windings on thoontpnt transformers of lsaidoircit and monitoring i1s`s'ociafedwith nid' windings.; 'of snpofviisry circuit comprising switching moans for con-A necting said supervisory clrciiit `with "s'oid jacks', an operatorsitilking sot', a tolk-ing key, a monitoring key, an' inoqnalityl ratio repeating coil in said ysi1i` civ`isoiy circliit, means coni-rolled by sndinking key `for o' crativ'ely associating lsaiid. coil with said .talE- ing `s`et,- and I'nansl 'controlled by -moiiito'ling. key for varying the rti'ojof the Winch ng'S 10i Said Coil.4

The combination with n re cater circuit comprislng ysiip'crvisory windings on 'the 2, Tlic combination with o cwjocloniont i outpiit transformers bf "Said circuit' .and `1 monitoring .jocks n ssocjinftedwfith said windings, of al.supers'isoryA circuit .compriing swiocninr fnicons for'connccting vsaid superi. y

visoryhcircuit with sid jocks, operators .equipmno ,talking key and n mitbi-hg in'iy,` and :ine-ans btrollcd' by th'jint 0poronion of sind `koos,fwirorco'yscid opo ions loo equipment ma `b i' oportiycly i'aftcd? ncjo'cing sind supcrvioony cncnio inch sind ilo.

' selective manner, la ringing key, a source of current associated therewith, and means controlled by the joint operation of said ring' ing key and said monitoring key whereby current from said lsource may be applied to said windings in a selective manner.

6. The combination 4with a repeater circuit comprising two line sections interconnected by repeater apparatus, supervisory windings on the output transformers of said ,y

repeaters, mpngitoringnjacks associated with said windings, and line jac in said line sections; of a supervisory v rcuit comprising switching-` means for connecting said supervisory circuit with e' er of said jacks, a monitoring ke ,a rin ng key, a plural1` ty of sources o different types of ringing current associated with said ringing key,

means controlled b the joint operation of said keys when said supervisory circuit isconnected to said monitoring jacks whereby lringing current may applied to said supervisory windings in a selective manner', and

means controlled `by said ringing key valone when, said supervisory circuitl is associated with one of said line jacks whereby ringing current from either o f said sources may be applied to said line'section.

The combination with a circuit comprismg two line sections interconnected by repeater apparatus composite ringer apparatus interconnecting said vline sections for ringing around said re eater'apparatus, supervisory Iwindings o n 51e output transformers of said repeaters, monitoring jacksv as'- sociated with said Windings,'and'1ine jacks in said line sections between said compositey ringer apparatus and said repeater apparatus; of a supervisory circuit comprising switching means for connecting said supervisory circuit with either of said jacks, a monitoring key, a ringing key, a source of 5 ringingv current associated with said-ringing key, means vcontrolledby the joint operation of said ke s when said supervisory circuit is connecte to -said monitoring jacks whereby ringing current may be applied to 'said supervisory vwindings, in a. selective manner, and means associated with said line jacks and said supervisory circuit and controlled by said ringing key alone when said supervisory circuit is associated with one of said line jacks whereby said composite ringer apparatus may be actuated to send ringing current out over said line section. v

In testimony whereof, I have signed -my' name to this specification this 10th day of 00 November 1921. j f

. 'HUGH F. SHOFFSTALL. 

